On 2 November 2003, we knew what was expected on election day 2004. Howard Dean would be the Democrat nominee for president, his young supporters would be passionate and energised but, if efforts to paint him as an anti-war liberal had succeeded, he might be facing a drubbing at the polls.

A year later, there is a different candidate challenging George W Bush and possibly a very different result at the polls.

From likely candidate to footnote: Howard Dean started 2004 badly

All that is certain is that there is uncertainty - about the result, possible challenges to voters and counts, and how the country will react to the eventual winner.

The campaign year began in earnest in January with a field of nine hopefuls vying to be chosen as the Democratic candidate through a series of primary elections and caucus votes.

Senator John Kerry looked down and out. Despite having switched campaign advisers, he was failing to create any kind of media buzz.

"Kerry will be president when the Red Sox win the World Series," a caller to an Iowa radio phone-in show said, using the baseball equivalent of "when the cows come home".

It may have seemed a safe analogy then, but it was in Iowa on 19 January that Mr Kerry began his comeback - and 10 months later that the Red Sox did indeed win the World Series for the first time in 86 years.

Warning

Mr Kerry's boost from his unexpected win in the Iowa caucus was helped by Mr Dean going into freefall, most notably with the panning he took for his now infamous "Dean scream" speech to supporters.

The Republican convention saw Mr Bush at his strongest

The next day, President Bush effectively launched his re-election campaign with his State of Union address, setting out a stark choice for voters and warning of the perils of changing leaders during a time of conflict. Even then, it was clear that the aftermath of the war in Iraq would vie with more traditional factors like the economy as key issues in the campaign.

Mr Kerry won his party vote in New Hampshire and became the clear frontrunner, so much so that the first attack ad of the season came in February, with the Bush campaign saying he was beholden to special interests.

February also brought the announcement by Ralph Nader that he would run again for president. Seen by many Democrats as the man who kept Al Gore out of the White House in 2000, he was later dropped by his Green Party, though he is on the ballot for the Reform Party in many states and could again have an effect on the result.

In March, Mr Kerry was riding high as the presumptive nominee after a series of wins on Super Tuesday.

Campaigning - and more importantly fund-raising - continued through the spring and the scandals of the abuse of Iraqi prisoners by US military personnel at the Abu Ghraib jail.

President Bush used the benefits of incumbency - guaranteed media coverage and no need to introduce himself to the electorate - to stay in the headlines without an overtly political campaign.

He also raised millions of dollars for his campaign - as did Mr Kerry as his party rallied round him.

The death of former President Ronald Reagan in June brought a brief truce between Republicans and Democrats, but any calm was soon shattered by the opening of Michael Moore's film Fahrenheit 9/11 - an overtly political documentary that some opponents said violated election year rules.

The final report of 9/11 Commission in July was seized on by both sides as aiding their cause as homeland security stayed at the forefront of the campaign.

Convention opportunities

Mr Kerry - still trying to become a household name and character for Americans - set out his credentials to be commander-in-chief with his first words to the Democrat convention that formally nominated him: "I'm John Kerry and I'm reporting for duty."

The intense media coverage - and feted return of former President Bill Clinton at the convention - raised Mr Kerry's profile and poll numbers, but did not give him a commanding lead.

John Kerry came out ahead after the first televised debate

It was soon followed by allegations from fellow Vietnam veterans that Mr Kerry did not deserve his war medals, forcing the campaign to respond.

As the Democrats were put on the back foot, the Republicans took a stride forward with a polished and effective convention.

Republican party stars invoked the memory of 9/11, and the strength and determination it brought out in the city worst affected by the attacks, New York. Mr Bush ended the convention with a powerful and emotional speech, leaving his campaign on a high in early September.

With the president back in the lead, Mr Kerry was once again looking like an also-ran, and hopes that Mr Clinton would use his campaigning passion had to be put on hold when the former president underwent heart surgery.

But then came the debates. With more than half the expected electorate watching, Mr Kerry clearly won the critical first of three televised head-to-heads with Mr Bush.

The other debates contained no knock-out punches, though the increasingly bitter campaign was highlighted by the increased use of personal insults by both men.

Even as the two sides tried to show how they were different, the late October polls continued to indicate that the two men were in a statistical dead heat across the country, while the swing states swung from one side to the other.

Missing mandate

In the final days of campaigning, celebrities were trotted out to excite and energise core supporters, while the candidates crossed into each other's territory to woo voters - Mr Kerry on a hunting trip and Mr Bush at a Catholic Mass.

The sometimes bitter campaign is affecting party supporters too

The long-awaited October surprise came in the way no-one expected, with the reappearance of an alive and healthy Osama Bin Laden, but in the end he may not have much of an impact.

A year on from the mistaken expectations of a Bush-Dean showdown, there is excitement and anticipation, but also fear and fatigue.

The one thing that is clear is that neither man has won over large sections of the electorate, and it is unlikely that whoever wins will be able to claim an overwhelming mandate in a politically polarised country.

Much has changed in the last year, and almost the only thing about the election that brings the country together is the hope that there will also be a change from four years ago, and that this campaign will end on 2 November.